| Field | Allowed values | Special characters |
|---|---|---|
| Minute | 0–59 | * , - / |
| Hour | 0–23 | * , - / |
| Day of month | 1–31 | * , - / ? |
| Month | 1–12 or JAN–DEC | * , - / |
| Day of week | 0–7 or SUN–SAT (0 and 7 = Sunday) | * , - / ? |
A cron expression is a compact notation for defining recurring time schedules.
Originally from Unix's cron daemon, cron expressions are now used
in GitHub Actions, AWS EventBridge, Kubernetes CronJobs, Cloudflare Workers,
and virtually every task scheduler in existence.
The five-field format is minute hour day-of-month month day-of-week.
Each field can be a specific value (9), a range (1-5),
a list (1,3,5), a wildcard (*), or a step (*/15).
Combinations are possible: 0 9 * * 1-5 means "9:00 AM, Monday through Friday."
Named shortcuts exist for common patterns: @hourly, @daily,
@weekly, @monthly, and @yearly. These are
widely supported and are often clearer than the equivalent numeric expression.
One persistent source of confusion: day-of-week numbering. Most systems treat 0 as Sunday,
but some treat 7 as Sunday too. The safest approach is to use named days (MON,
TUE, etc.) when your scheduler supports them, or to test your expression
against upcoming dates before shipping.
Cronfig runs entirely in your browser. There is no server, no tracking, no account required. The parser computes next run times locally against your device's clock and timezone. It works offline.
0 9 * * 1 means "every Monday at 9:00 AM."
@hourly (every hour), @daily (midnight every day),
@weekly (midnight every Sunday), @monthly (midnight, 1st of month),
@yearly (midnight, January 1st). Cronfig supports all of them.
*/5 in the minute field means "every 5 minutes."
0 */2 * * * means "every 2 hours at :00." Steps work in all fields.
0 9 * * * fires at 9AM UTC
— which is 4AM or 5AM Eastern depending on DST. Cronfig shows run times in your
browser's local timezone so you can sanity-check what the schedule actually means for you.
@Scheduled, and AWS Lambda all use this format —
for example, 0 0 9 * * MON-FRI (fire at 9:00:00 AM weekdays).
Unix cron and most cloud schedulers (GitHub Actions, Kubernetes CronJobs, CloudWatch Events)
use the standard 5-field format. Cronfig detects 6 fields and asks you to remove the
leading seconds field to convert it to standard format.
EnvLint — .env file validator · FeedLint — RSS/Atom feed validator · DiffLint — git diff linter · LinkScrub — strip tracking params from URLs · qrnch — QR code generator · hashchop — hash generator · jwtchop — JWT decoder · epochop — Unix timestamp · b64chop — Base64 encoder · csvchop — CSV to JSON · uuidchop — UUID generator · radish — stack trace analyzer · pxicons — pixel favicon editor · yamlchop — YAML validator · sqlchop — SQL formatter